For utilities, a worst-case scenario is a multiple-area, simultaneous, and extended service outage resulting in unhappy customers and high costs for restoration and lost power. In the U.S., for example, the estimated annual cost of outages ranges from $10 to $75 billion, with an average of $26 billion annually over 10 years.
The estimated annual cost of power outages in the U.S. ranges from $10 to $75 billion
Utilities use outage management systems (OMS) to manage the grid and restore power during a service interruption. An OMS identifies and predicts potential grid outages and manages restoration activities with the goal of reducing the economic impact of power outages.
The most advanced systems can reduce downtime and corresponding costs by up to 25%, but a traditional OMS has two basic shortcomings:
• Lack of a real-time representation of the smart grid network model
• Ineffective or no integration with the systems that monitor and control the grid
Although an OMS may function as expected, these gaps result in a fragmented network view for system operators that can lead to human error, unnecessary complications, and less-than-optimal workflows.
Challenge #1: An evolving network model
The prime objective of an OMS is to understand where a utility’s customers fit into its network, in order to analyze the location and extent of an outage. An accurate analysis depends upon the network model mapping out customer connections.
But maintaining an up-to-date model of the operational grid in an OMS is not simple. Distribution systems undergo daily changes due to operational configuration, network additions, and routine maintenance switching. Changes can originate from different sources, such as control center operations, maintenance and construction crews, and service personnel.
An obsolete network model can cause an OMS to misdiagnose an outage – which results in sending repair crews to the wrong location and extending the duration of an outage. Furthermore, operators may come to distrust or even discount the information an OMS provides.
Challenge #2: Integration of disparate tools
When systems integration is lacking, operators don’t have a clear view of their network. Many utilities create “workarounds” to compensate, frequently using a manual process to shuffle information from a SCADA system and/or distribution management system (DMS) to the OMS and back. This convoluted bidirectional navigation between systems can impact dispatching and cause mistakes and poor decisions during outages.
However, integrating real-time tools like a SCADA system or DMS with an OMS is problematic. Utilities prefer to operate their command-and-control systems on stand-alone, closed-loop networks to ensure performance and security. In addition, operations business units control these mission-critical systems rather than centralized corporate IT. This can result in less focus on standards and integration architecture, which can further complicate any integration initiatives.
Unique ADMS capabilities
With millions of network data points to process and various distributed energy resources to integrate, a traditional DMS cannot analyze the high data volumes needed to manage a smart grid. Instead, many utilities rely on an advanced distribution management system (ADMS).
An ADMS places the tools for outage analysis and crew dispatch alongside those for control, load flow, and grid optimization, which promotes a more responsive and less error-prone workflow. An ADMS eliminates the network modeling problem, enabling OMS functionality against the memory-resident, real-time model of SCADA / DMS. A single, high-performing network model for SCADA, DMS, and OMS improves accuracy and performance, and eliminates the need for data synchronization among disparate models.
Improved OMS performance
A smarter grid requires robust tools to manage both normal operations and emergencies. An OMS is vital to predicting and managing power outages. In addition, mobile OMS applications further empower field crews and make communication between crews and the control room more structured and reliable.
Combining an OMS with the tools and benefits of a DMS creates a powerful ADMS and greatly simplifies the work of grid operators to the benefit of both customers and utility companies.